From fa917381937c46824b005835038b1454e21421c3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADtor=20Santos=20Costa?= <vsc@dcc.fc.up.pt>
Date: Thu, 17 Jun 2010 00:33:57 +0100
Subject: [PATCH] extend SWI compatinbility.

---
 packages/PLStream/pl-incl.h | 14 ++++++++++-
 packages/PLStream/pl-yap.c  | 46 +++++++++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+), 1 deletion(-)

diff --git a/packages/PLStream/pl-incl.h b/packages/PLStream/pl-incl.h
index 718b446d1..478dc42f8 100755
--- a/packages/PLStream/pl-incl.h
+++ b/packages/PLStream/pl-incl.h
@@ -102,6 +102,8 @@ typedef enum
 typedef struct tempfile *	TempFile; 	/* pl-os.c */
 typedef struct canonical_dir *	CanonicalDir;	/* pl-os.c */
 typedef struct on_halt *	OnHalt;		/* pl-os.c */
+typedef struct extension_cell *	ExtensionCell;  /* pl-ext.c */
+typedef struct initialise_handle * InitialiseHandle;
 
 /* The GD global variable */
 typedef struct {
@@ -151,6 +153,17 @@ typedef struct {
     atom_t     *for_code[256];		/* code --> one-char-atom */
   } atoms;
 
+  struct
+  { ExtensionCell _ext_head;		/* head of registered extensions */
+    ExtensionCell _ext_tail;		/* tail of this chain */
+
+    InitialiseHandle initialise_head;	/* PL_initialise_hook() */
+    InitialiseHandle initialise_tail;
+    PL_dispatch_hook_t dispatch_events; /* PL_dispatch_hook() */
+
+    int		  _loaded;		/* system extensions are loaded */
+  } foreign;
+
 } gds_t;
 
 extern gds_t gds;
@@ -498,7 +511,6 @@ typedef double			real;
 
 #endif
 
-#define PL_dispatch(FD, COM)
 extern int PL_unify_char(term_t chr, int c, int how);
 extern int PL_get_char(term_t chr, int *c, int eof);
 extern int PL_get_text(term_t l, PL_chars_t *text, int flags);
diff --git a/packages/PLStream/pl-yap.c b/packages/PLStream/pl-yap.c
index 25a9d2c8c..ae96e86e3 100644
--- a/packages/PLStream/pl-yap.c
+++ b/packages/PLStream/pl-yap.c
@@ -608,3 +608,49 @@ warning(const char *fm, ...)
   return TRUE;
 }
 
+#if defined(HAVE_SELECT) && !defined(__WINDOWS__)
+
+#ifdef __WINDOWS__
+#include <winsock2.h>
+#endif
+
+static int
+input_on_fd(int fd)
+{ fd_set rfds;
+  struct timeval tv;
+
+  FD_ZERO(&rfds);
+  FD_SET(fd, &rfds);
+  tv.tv_sec = 0;
+  tv.tv_usec = 0;
+
+  return select(fd+1, &rfds, NULL, NULL, &tv) != 0;
+}
+
+#else
+#define input_on_fd(fd) 1
+#endif
+
+
+X_API int
+PL_dispatch(int fd, int wait)
+{ if ( wait == PL_DISPATCH_INSTALLED )
+    return GD->foreign.dispatch_events ? TRUE : FALSE;
+
+  if ( GD->foreign.dispatch_events && PL_thread_self() == 1 )
+  { if ( wait == PL_DISPATCH_WAIT )
+    { while( !input_on_fd(fd) )
+      { if ( PL_handle_signals() < 0 )
+	  return FALSE;
+	(*GD->foreign.dispatch_events)(fd);
+      }
+    } else
+    { (*GD->foreign.dispatch_events)(fd);
+      if ( PL_handle_signals() < 0 )
+	  return FALSE;
+    }
+  }
+
+  return TRUE;
+}
+